∑2 versions exist! The original has a copyright screen and the other doesn't, although it's not known if the game itself differs.

∑There is code in the program that displays reserve ship icons (like the arcade), but it was disabled presumably since the maximum # of ships that can be displayed is only
6 (the reserve counter goes up to 9). To activate this code, change the two bytes starting at $04ab from $a9 $00 into $a5 $bc.

∑At 1,000 points, a wave starts with 6 large asteroids. At 15,000 itís 8 (maximum). This is not mentioned in the manual. If you try to break all 8 into 2 ďmediumsĒ each, 3
of them will only break down into 1 medium each, leaving 13 mediums maximum on-screen, but itís possible to get a maximum of 14 small asteroids on-screen. {Scott Stilphen}

∑The color of your shots alternates between blue and pink (see picture). The saucerís shots are all pink.

∑When a saucer is on the screen, moving the Difficulty switch to B causes the saucer to immediately disappear!

∑An addendum sheet was later included, which corrects an error in the manual about when UFOs appear in the game (the manual says they wonít until you reach 15k; the sheet
says they will occasionally attack between 7,500 and 15k and always after that point). It also explains the dark area on the left side of the screen (the HMOVE line area).

∑BUG: Your shots arenít aligned with the nose of your ship for every position.

∑BUG: Sprite-collision detection isnít always accurate. Occasionally you might graze an asteroid unharmed, or your shots will pass through asteroids and saucers with no effect. This is most notable in an area near
the left border. If you approach it from the right (moving left) notice when your shipís movement hesitates for a spit-second- thatís the right edge of this area (the left edge being the border). While in this area, you can pass through any asteroids that approach you from the left side w/o harm, until nearly the whole asteroid is visible (so the large ones are best for this trick), as will your shots. {Scott Stilphen}

∑

FRYING:
Hold down RESET and fry until you see 2 asteroids on the right side of the screen. Every game version will then have all white (slow moving) asteroids that start in the same spot and drift to the right, and a ďsafeĒ (predictable) hyperspace (youíll always appear in the upper right corner). All saucers will appear from the same spot (the upper left corner) and move straight across the top of the screen (the large one will continually shoot up while the little one will fire left and down).
Also, small saucers will appear around 7,300 points and continue to do so until the score rolls (see video). {Scott Stilphen}